AKG Motorsport Rear Trailing Arm Bushings, Spherical – E36, E46, Z4Product Description These BMW E36, E46, Z4 Aluminum Rear Trailing Arm Bushings with spherical bearings eliminate movement of the rear trailing arms preventing geometry changes and keeping alignment consistent. The factory rubber rear trailing arm bushings are soft and wear out quickly, creating fluctuations in suspension geometry that adversely affects everything from cornering to braking stability. Eliminate these issues with our BMW E36, E46, Z4